Circuit-breaker



J. B. MAcNElLL.

CIRCUIT BREAKER.

APPLICATION FILED NOV. 20. I920.

1,395,348. Patented Nov. 1, 1921.

I WITNESSES: INVENTOR yfg'gm 170/? 5 /W6/V/// ATTORNEY UNITED STATES PATENT OFFICE.

JOHN B. MACNEILL, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

CIRCUIT-BREAKER.

Specification of Letters Patent.

Patented Nov. 1, 1921.

Application filed November 20, 1920. Serial 1%. 425,343.

T 0 all whom it may concern:

Be it known that I, JOHN B. MAoNEILL, a citizen of the United States, and a resident of Wilkinsbur in the county of Allegheny and State of ennsylvania, have invented a new and useful Improvement in Circuit- Breakers, of which the following is a specification.

My invention relates to electric circuit breakers and particularly to those used in opening and closing high-voltage lines, which employ, in addition to the brush contacting members, arcing tips to prevent arcing between the brush contacts.

My invention has for its object the provision of mechanical means for securing a more effective contacting engagement of the brushes and the arcing tips with their coacting contacting members, and means whereby the magnetic forces which are present in v mechanism of this kind are utilized to secure a more effective engagement between the varlous contact surfaces.

Circuit breakers are usually constructed in such manner that the path of the electric current therethrough is of substantially U- shape, and the magnetic forces set up in that portion of the circuit exercises an expulsive force which tends to distort the switch parts and break the circuit.

In my device, the magnetic forces are utilized to secure a still firmer engagement between the contact members of the switch.

Another objection to the ordinary type of circuit breaker resides in the fact that its arcing tips, which are usually of the springheld plunger type, are apt to bind in their guideways, under the action of the magnetic of the contact members of a circuit breaker,

with my invention embodied therein.

An operating rod 1 is actuated to move a movable, or bridging, contact member 2 into 6 which are supported by conductors or studs 7 and 8, respectively.

A pair of arcing tips 9 and 10 are pivoted at 11 and 12, to the brackets 5 and 6, respectively, and each has an end of a spring guide member 13 pivoted therein, the other end of each guide member being slidably supported by extensions on brackets 5 and 6, res ectively.

ach of the tips 9 and 10 is acted upon by a compression spring 14 which assists in maintaining it in engagement with one of the arcing tips 15 that are carried on the movable contact member 2. A lug 16 is provided on each of the arcing tips 9 and 10, to limit its movementwhen the contact member 2 has been moved to open position.

The electric current, in passing through the circuit breaker, in the direction indicated by the arrows, follows a substantially U- shaped path and, therefore, creates opposing magnetic forces in the zone lying between the conductors 7 and 8. These magnetic forces exert a repulsive action on the contacting members and tend to distort them, but, because the movable contact member 2 is positively held in position by the rod 7, such forces tend to press the brushes 3 and 4 more firmly into engagement with the member 2 and exert a repulsive action on the arcing tips 9 and 10 also, which results in a more efi'ectiveengagement between them and the arcing tips 15.

When it is-desired to open the circuit, the contact member 2 is lowered to break its contact with brushes 3 and 4, and the arcing tips serve to prevent arcing between the main contact members during the opening or closing of the circuit. A pair of flexible shunt members 18 are provided to carry the current when the brush contact is broken, in order that current may flow through the arcing tips until their contact also is broken. It will be seen from the foregoing that my arrangement of switch parts is such that the magnetic forces present in constructions of this kind are utilized to secure a more efiec- .tive contact instead of being permitted to exercise their tendency to render the action of the switch less effective.

My invention is not limited to the specific structure illustrated, as it may be variously modified without departing from the spirit and scope thereof, as set forth in the appended claims.

I claim as my invention 1. In combination, in a circuit breaker, a movable contact member, a pair of station- 'ary contact members, a pair of arcing tips pivotally mounted on the stationary contact members, springs normally exerting tension to maintain the arcing tips in engagement with the movable contact member, and stop members limiting the movementof the arcing tips, said tips being so disposed that the magnetic forces set up by the passage of current through the circuit breaker act against the tips to assist the springs in maintaining the said engagement.

2. In a circuit breaker, a pair of stationary contact members, a pair of arcing tips pivotally mounted on the stationary contact members, a movablecontact member, a pair-of arcing. tips carried by the movable contact member, and means whereby the magnetic stresses set up by the passage of currentthrough the circuit breaker act to normally hold the pivoted arcing tips in engagement with the arcing tips carried by.

the movable. contact member.

3. In a circuit breaker, a pair of stationary contact members, a movable contact member, a pair of movable arcing tips, and means whereby the magnetic stresses set up by the passage of current through the circuit breaker act to normally maintain the arcing tips in engagement with the movable contact member.

4. In a circuit breaker, a pair of fixedly mounted contact members, a pair of pivotally mounted contact members normally held in resilient engagement with the fixedly mounted contact members, and means whereby the magnetic forces incident to current traversing the contact members maintains them in engagement.

5. In combination, in a circuit breaker,

main contact members movable with respect to each other, a fixedly mounted arcing tip,

a pivotally mounted arcing tip, and. magnetic means for maintaining said tips in contact until the main contact members are moved apart a distance suficientto avoid arcing. r

6. In a circuit breaker, the combination with a pair of co-acting main contact members, of two relatively movable auxiliary contact members and means whereby the magnetic forces incident to current traversing the contact members maintains the auxiliary contact membersin engagement. 7. In a circuit breaker, the combination with two relatively movable main contact members, of two auxiliary, contact members, one of which is movably supported by one of the main, contact members, and means whereby the magnetic forces incident to current traversing the contact members maintains the auxiliary contact members in enga ement.

n testimony whereof, I have hereunto subscribed my name this 12th day of November, 1920. 4

Jenn B. MACNEILL. 

